Seam-trimming mechanism for sewing-machines.



H. G. EDMONDS. SEAM TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JUNE 26, I914.

' Patented Mar. 7, 191 6.

THE COLUMBIA PLANDGRAPH co., WASHINGTON, n. c.

her 1 and arm 9 formed as a part thereof being beveled to form a cutting edge 11, and the adjacent edge of the toggle member 2 and the arm 10 left plain to provide a bearing surface for this knife. As better illustrated in Figs. 1 and 2, the cutting edge 11 and the bearing face 12 of the toggle members 1 and 2 respectively are formed on the arc of a circle, the pivotal connection at 3 and 8 being the centers of these arcuate edges and the two toggle members made of such extent that the cutting edge 11 come to a bearing relation against the surface edge 12 and material placed between the two members as they are swung from the position indicated in Fig. 1 to the relation in Fig. 2', will be cut or abraded to cause aseverance thereof. It will be understood that this structure as described is placed at a point adjacent the bearing foot of the sewing machine and that in consequence the point of cutting or severing of the fabric will be at all times at a uniformly same distance from the seam as run by the machine. It is preferable that this trimming mechanism be actuated to operate in conjunction with the forward movement of the material being sewn through the force feed of the fabric feeding mechanism.

An oscillating arm 13 is pivotally connected at 14 with the toggle member 2 and at its opposite end this arm or lever 13 may be connected with any of the moving parts of the machine which will transmit power thereto to cause a reciprocatory movement of the toggle member 2 upon each movement of the fabric feed mechanism. The toggle member 1 at a point beyond the extent of the knife edge 11 has a notch 15 formed to extend into the body portion thereof and a tongue 16 formed to extend from the adjacent edge of the toggle member 2 fits in this notch, the spur 17 being provided to hold the tongue 16 in place and the member 2 having a notch 18 to accommodate this spur 17 as the two members are rocked due to the movement of the oscillating arm 18 and the consequent transmitted movement from the toggle member 2 by the engagement of the tongue 16 in the notch 15.

As shown in Fig. 5, the edge 12 of the toggle member 2 is preferably made to incline at an angle from a right angular position with respect to the side faces of this member and in such relation that the higher point is disposed away from the position occupied by the needle of the machine. The toggle member 2 has a plurality of notches cut vent gripping edges to engage with the waste edge of the fabric as it passes beneath the pressure foot and this waste edge which is trimmed from the main body of the fabric will be carried along at the same rate of speed as the main article or garment being sewed which derives its movementfrom the feeding mechanism of the sewing machine structure. To prevent dirt and lint clogging in the parts of the trimming mechanism and thus impeding the operation thereof, the metal of the body portion of the toggle member 1 is cut away at the inner end or throat of the notch 15 in such a manner that for eign matter which would otherwise be packed in this notch by the movement of the tongue 16 therein is automatically forced on through the notch by this same movement of the tongue, also it is desirable that the tongue 16 be beveled on one of its faces and that in a like manner the spur 17 be formed fabric to be sewed, in its travel through the machine beneath the bearing foot and in the path of the needle passes in the direction indicated by the arrow in Fig. 1, the machine is in normal operation and motion is transmitted through the oscillating arm 13 to cause the toggle member 2 to be rocked around its pivot point, this movement being transmitted to the toggle member 1 and causing the two toggle members to be brought to the position indicated in Fig. 2 where the knife edge 11 has rocked against the edge 12 a distance equal to the forward movement of the fabric by the fabric feed mechanism of the sewing machine and the engagement of the fabric between these two edges causes a cutting or abrading action to sever the goods at that point, the fabric feed mechanism of the sewing machine acting to carry the main body of the fabric along in the desired path and the engagement of the teeth 19 of the toggle member 2 insuring that the edge trimmed from the fabric adjacent the seam will be carried to a point where it will not clog in the operating parts either of the sewing machine mechanism or of the trimming mechanism.

From the foregoing it will be seen that I have provided a trimming mechanism to be used in connection with a sewing machine which is positive and efficient in its operaquence the notch is formed in the lower toggle member or the toggle member which has the bearing face provided thereon. With such a structure, it is only natural that the greatest pressure is brought to bear against the toggle member having the broad flat edge and in consequence of the weakening of this member by placing the notch therein the trimming mechanism as shown in the patents referred to has not been so'highly durable, the part weakened by the placing of the notch being the part which received the greatest strain, and by the arrangement of the parts as set forth as a part of my invention, it will be seen that this objection is overcome and each of the toggle members is made to have its full bodily strength, also it will be obvious that as the tongue 16 has its movement in its oscillation in an upward direction any lint or dirt which may be collected thereon is not forced down into the operating mechanism of the sewing machine but rather the movement of the'parts is such that lint and other foreign matter is carried away from the operating mechanism.

While I have herein shown and described one specific form of my invention, it will be understood that slight changes might be made in the form and arrangement of the several parts without departing from the spirit and scope of my invention, and hence I do not wish to be limited thereto except for such limitations as the claims may import.

I claim l. A trimming mechanism including two toggle members mounted in cooperative relation, the adjacent edge of one of said members made beveled to one side, and teeth formed through the side edge of said member to extend into said adjacent edge in such relation that gripping'edges are presented thereon to engage with the fabric.

2. A trimming mechanism including up per and lower toggle members mounted in cooperative relation, the adjacent edge of one of said members shaped to form a flat bearing face beveled to one side, and teeth formed in the side of said member to extend into said fiat bearing face on that edge at which the acute angle is formed.

3. A trimming mechanism including upper and lower toggle members mounted in cooperative relation, the adjacent face of 7 said uppermember shaped to form a knife edge, said lower member formed on the adjacent edge thereof to provide a flat bearing surface beveled slightly to one side, a tongue formed on said lower member to extend from the bearing face thereof, said upper member providedwith a notch to receive the tongue to cause the two members to be connected in a relation to have cooperative movement, and teeth formed in one side of said lower toggle member to extend through said bearingfface at that edge forming an acute angle with the side of said toggle member.

4. A trimming mechanism adapted for use with a sewing machine including a lower toggle member to be mounted beneath the work-supporting table, an upper toggle member mounted in cooperative relation above said lower toggle member, the adjacent face of said upper member shaped to form a knife edge, said lower member formed on the adjacent edge thereof tofprovide a flat bearing surface beveled slightly to one side and the position of the same is such that the obtuse angle of said bearing surface may be placed in line with the surface of the work-supporting table and the acute angle at the opposite side will project slightly above said work-supporting table, a connection between said toggle members by which simultaneous movement is given thereto, and teeth formed on one side of said lower toggle member by providing notches which extend through the bearing face thereof at that edge forming an acute angle with the side of said toggle member to engage with and feed the fabric forward.

In testimony whereof I aflix my signature in presence of two witnesses.

HENRY G. EDMONDS.

Witnesses:

HARRY SHERBURNE, CHAS. E. HARDINS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

